There is a story about the Sakyamuni:
Once a disciple walked up to the Sakyamuni and said:
I want Happiness.
The Sakyamuni said:
Drop the “I” and the “Want” and all you are left with is “Happiness”.
The “I” is Ego. The “Want” is selfish desire, instead of selfless action.
The main key to Happiness is to do everything without expectations and without ego.
It is your right and prerogative to offer your love and sacrifice for someone.
Similarly it is their right and prerogative to recognize that love and sacrifice.
This is extremely confusing.
You can offer love and sacrifice, sometimes for decades, and still not be recognized or even thanked, but you cannot call the person who did not recognize it ungrateful.
You only have a right to accept, not a right to expect.
Is it right for you to expect?
Was it not just you duty to offer love and sacrifice for all that the other person had done for you in the past?
What I say is nothing new.
It is a fundamental precept of the Sanathan Dharma and is repeated many times.
In fact Vivekanand himself said:
Do you ask anything from your children in return for what you have given them?
It is your duty to work for them, and there the matter ends.
In whatever you do for a particular person, a city, or a state, assume the same attitude towards it as you have towards your children — expect nothing in return.
Learn to love your children like nurse in the kindergarten loves them – she is taking care of them, she is teaching them things, feeding them, making sure they are safe.
But when the time comes that they move on, she lets them go.
She loves them without attachment.
The Gita says:
“Be focused on action and not on the fruits of action.
Do not become confused in attachment to the fruit of your actions and do not become confused in the desire for inaction”.
But what is action?
The Gita says:
He who sees inaction in action and action in inaction is wise among men.
Action means doing your duty without attachment to the fruits of your actions and always dedicated to Brahman.
You must do your duty regardless of what will happen to the results and without any expectation of the fruits of that action.
The Vishṇu Puraṇa says:
“That is action, which does not promote attachment; that is knowledge which liberates.
All other action is a mere effort/hardship; all other knowledge is merely another skill/craftsmanship.”
Apply this golden rule to every facet of your life and you will immediately drop the heavy baggage of expectations and all the associated disappointment that comes with it when your expectations are not met.